1. Area of Invention
The invention relates to guiding devices for use by persons including, but not limited to, the blind, visually impaired, security personnel, emergency personnel and fire fighters.
2. Prior Art
Guiding devices have been designed in which a signal is sent out from the device and is reflected from an object positioned above the walking level and returned to the device, this in the manner of a simplified type of radar or sonar to thereby operate a signalling means to indicate to the user that an object is in front of him. Systems of this type have, however, proven unsatisfactory due to difficulty in the interpretation of the types of signals returned in which a user can often confuse background objects with objects that are in the foreground. Such prior art is reflected in U.S. Pat. No. 3,360,775 (1967) to Schroeder.
A later device of this type is reflected in U.S. Pat. No. 3,718,896 (1973) to Moat in which, provided within a blindman's cane is a transmitter that transmits pulses of energy in a directional manner and a receiver which accepts the first or earliest returned pulses, rejecting all others for a predetermined period. Thereby, only those pulses relative to objects which are in the foreground are processed by the system.
More sophisticated systems, such as that reflected in U.S. Pat. No. 4,660,022, involve the use of sound generators selectably positioned at different locations, typically within corridors of a building or shopping mall in which a signal from the cane will actuate the sound generator to convey important information to the blind person, such as “intersection approaching,” “bathroom approaching,” or any other information deemed important for a blind person to obtain when in public places such as pedestrian crossings, railroad stations, airports, and passageways within public buildings. This approach however requires the positioning of such sound generators at numerous places within the public area or space of interest.
In recent years, the above has been improved upon through such approaches as radio-frequency guidance system for visually handicapped, as are reflected in U.S. Pat. No. 5,144,294 (1992) to Alonzi, et al, and U.S. Pat. No. 6,097,305 (2000) to Im, et al. Also, prior art of more recent vintage teaches complete electronic autorouting or navigation systems for the blind, as is reflected in U.S. Pat. No. 5,806,017 (1998) to Hancock, in which the entire routing or itinerary of a visually impaired person may be programmed at the beginning of a trip or may be programmed on a daily, weekly, or task-by-task basis.
The prior art, as reflected in the above, is unquestionably of great value to the visually impaired person if he is fortunate enough to live or work within an area which is able to afford systems of such sophistication.
Also, a further shortcoming of such prior art is that the visually handicapped person is readily identifiable as such by reason of the requirement that he at all times make use of a cane or the like. Thereby, the present invention seeks to address both the issue of cost and, particularly, the issue of social stigma attached to the use of a cane by a person who becomes visually impaired due to illness, accident, or physical condition later in life. Accordingly, within the present invention addresses an alternative to the historic need for use of a cane by blind persons or others having impediments in their mobility or recollection of how to navigate from one point to another.